Why It's So Hard to Lose Weight, According to a Nutrition Scientist I’m seeking commentary from PhD-level nutrition scientists, obesity researchers, or experts in metabolism and appetite regulation to explain the biological and physiological reasons weight loss can be difficult. Specifically looking for evidence-based insight on: • Metabolic adaptation and adaptive thermogenesis • Hormonal shifts (e.g., leptin, ghrelin, insulin) during weight loss • Set point theory and body weight regulation • The role of sleep, stress, and inflammation • Environmental and ultra-processed food influences on appetite regulation • Why “eat less, move more” oversimplifies the issue Please provide: • 2–4 sentences of clear, consumer-friendly commentary • Relevant credentials and current role • Links to published research (if applicable)

(1) Our bodies are wired for survival, not aesthetics -- so when we lose weight, the body thinks it's in trouble. Metabolic adaptation kicks in, slowing energy use and making it harder to burn calories. It's like your body putting the brakes on, even when you're still trying to drive forward. (2) Hormones don't stay quiet during weight loss. Ghrelin (the hunger hormone) goes up, leptin (which tells you you're full) goes down -- so you're hungrier even while eating less. It's not weakness; it's biology trying to restore "normal." (3) I think of the set point theory like the body's emotional home -- it remembers where it felt safest and tries to return there. So even after progress, undoing that internal comfort zone takes more than willpower -- it takes patience, habit shifts, and often emotional healing too. (4) When you're sleep-deprived or stressed, the body floods with cortisol, which ramps up cravings -- especially for sugar and carbs. Add inflammation into the mix and your body resists change like it's defending itself, not betraying you. (5) Ultra-processed foods are designed to bypass natural cues like fullness -- they light up dopamine faster than a hug or a beautiful sky. In a world built for overstimulation, learning to eat intuitively becomes an act of rebellion. (6) "Eat less, move more" assumes everyone starts from the same place, but so many women I meet are already eating less -- and still feel stuck. Weight is deeply tied to identity, trauma, hormones, culture... it's never just math. Credentials: Julia Pukhalskaia, Founder of Mermaid Way -- a wellness and intimatewear brand inspired by body freedom. I studied design in Milan and built our brand around softness, not shame. LinkedIn: https://linkedin.com/in/julia-pukhalskaia-9b0b98337 Headshot: https://drive.google.com/file/d/1fuG5wNimYVBgbDxudGzERkOebhQlci-4/view?usp=sharing

1 / After we opened, I learned fast that stress, poor sleep, and energy crashes often drove guests to overeat or crave comfort foods--and it's not just willpower. Stress ramps up cortisol, which can increase fat storage and hunger signals. Lack of sleep? That drops leptin (the "I'm full" hormone) and raises ghrelin (the "I'm hungry" one). One guest said after a week of full nights and sauna sessions, her afternoon sugar cravings vanished. 2 / The "eat less, move more" mantra doesn't match the biology. Our bodies fight fat loss with adaptive thermogenesis--basically burning fewer calories as we lose weight. It's not you failing; it's your body trying to protect what it thinks it's losing for survival. That helped me rethink how we talk about wellness goals at the spa--progress isn't linear, and habits matter more than hard numbers. Damien Zouaoui Co-Founder, Oakwell Beer Spa, Denver https://linkedin.com/in/damienzouaoui

(1) When people lose weight, their metabolism adjusts in a process called adaptive thermogenesis. The body becomes more efficient--burning fewer calories at rest and during activity--because it perceives weight loss as a threat to its energy reserves. This can significantly reduce daily energy expenditure and create a "plateau" effect despite unchanged effort. (2) Hormonal shifts complicate things further. Leptin (which signals fullness) drops, while ghrelin (which triggers hunger) rises, leaving people hungrier and less satisfied even when eating the same foods. Insulin sensitivity may also change, affecting how efficiently the body stores and uses energy. (3) There's strong evidence for a biological set point--essentially a weight range the brain tries to maintain. If you go below it, the body pushes back through hormonal, neurological, and behavioral changes. It's not impossible to change the set point long-term, but it's slow and requires sustained effort. (4) Chronic stress, poor sleep, and systemic inflammation all affect appetite regulation and energy metabolism. For example, high cortisol from stress encourages fat storage and disrupts glucose handling. We've seen in our R&D that even small improvements in sleep hygiene can influence appetite signals. (5) Ultra-processed foods hijack the brain's reward systems and override normal satiety signaling. They're engineered for hyper-palatability--often combining sugar, fat, and salt in ways that drive passive overconsumption. That undermines any "moderation" strategy, especially when food environments are so saturated with these products. (6) "Eat less, move more" oversimplifies what is really a tightly regulated survival system. Yes, calorie balance matters, but without addressing hormonal responses, food environment, stress, and metabolism, it becomes a demoralizing cycle of blame and burnout. Hans Graubard Co-Founder & COO, Happy V https://www.linkedin.com/in/hansgraubard/ https://happyv.com/cdn/shop/files/happyv_team_Hans.jpg

Weight loss is biologically difficult because the body interprets calorie restriction as a survival threat. Resting energy expenditure drops more than predicted (adaptive thermogenesis), leptin declines, ghrelin rises, and appetite increases. Add poor sleep, chronic stress (elevated cortisol), low-grade inflammation, and ultra-processed foods engineered for hyper-palatability and rapid glucose absorption, and the simple advice to "eat less, move more" ignores a tightly regulated neuroendocrine system designed to resist weight loss. Sustainable fat loss works best when we protect lean mass, stabilize blood sugar, improve sleep, and reduce stress

I am Dr. Cameron Rokhsar, a board certified dermatologist and laser surgeon in New York, and I see how biology can fight your best intentions. When you lose fat, your body acts like something is wrong. It defends a set point through appetite signals and energy saving responses tied to leptin and brain based regulation, so willpower alone is not the whole story. I also explain why "eat less, move more" feels like pushing uphill. Adaptive thermogenesis can linger and favor rapid fat regain during "catch up" periods. Food environment matters too. In a controlled crossover trial, simply slowing eating rate within ultra processed diets lowered intake by about 369 kcal per day and reduced fat mass by 0.43 kg in two weeks. Research links: 1) https://pubmed.ncbi.nlm.nih.gov/41314613/ 2) https://pmc.ncbi.nlm.nih.gov/articles/PMC12678223/